Atraumatic delivery system

Abstract

The present disclosure relates generally to the field of medical devices. In particular, the present disclosure relates to delivery systems configured to position a distal portion of a medical device within a restricted anatomical area. In one example, a delivery system may include a flexible elongate member with an inner member within a lumen of the flexible elongate member. A stent may be constrained therebetween. The stent may be configured to move between a first configuration to a second deployed configuration when unconstrained from the flexible elongate member. When the stent moves from the first configuration to the second configuration, the inner member may change from a first length to a second, shorter length. Other embodiments are contemplated.

What is claimed is: 
     
         1 . A delivery system, comprising:
 a flexible elongate member;   an inner member slidably disposed within a lumen of the flexible elongate member; and   a stent disposed in a first constrained configuration between a distal portion of the flexible elongate member and a distal portion of the inner member;   wherein the stent is configured to move from the first constrained configuration to a second deployed configuration when unconstrained from the flexible elongate member; and   wherein the distal portion of the inner member includes a first thickness and the remaining portion of the inner member includes a second thickness, the first thickness being less than the second thickness.   
     
     
         2 . The delivery system of  claim 1 , wherein the inner member transitions between a first length and a second length as the stent is unconstrained. 
     
     
         3 . The delivery system of  claim 2 , wherein the stent is unconstrained from the flexible elongate member by moving the inner member relative to the flexible elongate member, moving the flexible elongate member relative to the inner member, or moving both the inner member and the flexible elongate member relative to each other. 
     
     
         4 . The delivery system of  claim 3 , further comprising a handle operatively attached to a proximal end of the flexible elongate member, wherein the handle is configured to move between a first position to proximally retract the flexible elongate member relative to the inner member and a second position to distally extend the flexible elongate member relative to the inner member. 
     
     
         5 . The delivery system of  claim 1 , wherein the distal portion of the inner member is disposed within a distal portion of the stent in the first constrained configuration, in the second deployed configuration, or in both the constrained configuration and the deployed configuration. 
     
     
         6 . The delivery system of  claim 1 , wherein the distal portion of the inner member is formed of a shape-memory material. 
     
     
         7 . The delivery system of  claim 1 , further comprising a tissue penetrating element on a distal end of the inner member, the tissue penetrating element configured to form an opening in tissue. 
     
     
         8 . The delivery system of  claim 7 , wherein the tissue penetrating element comprises an electrically conductive tip. 
     
     
         9 . A delivery system, comprising:
 a flexible elongate member;   an inner member slidably disposed within a lumen of the flexible elongate member; and   a stent loaded in a first constrained configuration between a distal portion of the flexible elongate member and a distal portion of the inner member;   wherein the stent is configured to move from the first constrained configuration to a second deployed configuration when unconstrained from the flexible elongate member;   wherein a distal portion of the inner member is configured to move between a first length when disposed within the distal portion of the flexible elongate member and a second length when the stent is unconstrained from the flexible elongate member, the first length being greater than the second length; and   wherein the distal portion of the inner member includes a first thickness and the remaining portion of the inner member includes a second thickness, the first thickness being less than the second thickness.   
     
     
         10 . The delivery system of  claim 9 , wherein the inner member transitions between the first length and the second length as the stent is unconstrained. 
     
     
         11 . The delivery system of  claim 9 , wherein, when the flexible elongate member is distally extended, the distal portion of the inner member moves from the second length to the first length. 
     
     
         12 . The delivery system of  claim 9 , wherein the distal portion of the inner member includes a plurality of loops, and wherein a diameter of each loop at the first length, when the stent is in the first constrained configuration, is less than its respective diameter at the second length, when the stent is in the second deployed configuration. 
     
     
         13 . The delivery system of  claim 9 , wherein the distal portion of the inner member is disposed within a distal portion of the stent in the first constrained configuration, in the second deployed configuration, or in both. 
     
     
         14 . The delivery system of  claim 9 , wherein the distal portion of the inner member is formed of a shape-memory material. 
     
     
         15 . The delivery system of  claim 9 , further comprising a tissue penetrating element on a distal end of the inner member, the tissue penetrating element configured to form an opening in tissue. 
     
     
         16 . The delivery system of  claim 15 , wherein the tissue penetrating element comprises an electrically conductive tip. 
     
     
         17 . A method, comprising:
 advancing a delivery system into a patient to position a distal end of the delivery system adjacent to a target tissue;   penetrating a wall of the target tissue to position a distal portion of the delivery system; and   proximally retracting a flexible elongate member of the delivery system relative to an inner member of the delivery system extending within a lumen of the flexible elongate member, such that a distal portion of the inner member moves from a first length, when constrained within the lumen of the flexible elongate member, to a second length, when unconstrained from the flexible elongate member.   
     
     
         18 . The method of  claim 17 , further comprising:
 proximally retracting the delivery system relative to the target tissue; and   proximally retracting the flexible elongate member relative to the inner member.   
     
     
         19 . The method according to  claim 17 , wherein the target tissue includes a first body lumen and a second body lumen. 
     
     
         20 . The method according to  claim 17 , wherein the distal portion of the inner member is pre-formed in a plurality of loops, curls, waves, peaks and valleys, or combinations thereof, thereby forming a foreshortened configuration as the second configuration when unconstrained from the flexible elongate member.